There’s an old adage about how fighting can be good for your relationship. And for many people it can be: The makeup sex alone can be worth a passionate argument over the best way to fold socks. (Apparently there are multiple ways to fold socks—clearly, your way is wrong.)

But if you’re living with a chronic illness—as half of all Americans are—then you may want to check any unnecessary bickering. According to a recent study published in the Annals of Behavioral Medicine, the only thing worse than living with a chronic condition is fighting with your partner while living with a chronic condition.

Researchers were interested in getting a better understanding of how the day-to-day interactions in a marriage impact the health of a person living with a chronic disease. One older study found that when a wife reported more positive interactions during the day, her husband slept better that night; another study found that couples who were more physically intimate had lower levels of cortisol (the stress hormone).

In the current study, the authors focused on two groups of people: 145 patients who’d been diagnosed with osteoarthritis in the knee and 129 patients with type 2 diabetes. Participants kept daily diaries for 22 and 24 days, reporting on how tense or enjoyable their interactions were with their spouses. They also rated their general mood (ranging from frustrated to joyful) and how severe their symptoms felt.

Through their analysis, researchers found that “negative marital interactions may play a role in symptom exacerbation.” In both groups, patients were in a worse mood on days when they reported more tension than usual with their partner. That, in turn, led to more severe symptoms or pain. Additionally, the participants with arthritis appeared to get stuck in a terrible cycle: When they fought with their partners and subsequently felt physically worse, their pain often carried over to the next day, which led to more tensions with their partner.

These results could have some serious implications for health: As the researchers point out, people with “severe knee osteoarthritic pain become disabled at a faster rate, and individuals with uncontrolled diabetes are at risk for multiple health complications including neuropathy, blindness, and kidney disease.”

Lynn Martire, one of the study’s authors and a professor of human development and family studies at Penn State, pointed out how important it was that they were able to see this association in two different groups of participants with two different diseases. "The findings gave us insight into how marriage might affect health, which is important for people dealing with chronic conditions like arthritis or diabetes," she said in a statement.

Alternatively, it’s important to consider how health might affect marriage. In fact, a 2015 study suggested that the onset of a wife’s illness later in life is associated with an elevated risk of divorce (though the same wasn’t found when the husband became ill). An older report found that women who had a serious illness were seven times as likely to become separated or divorced as their male counterparts.

So, what do you do if your or your partner’s illness is stressing out your marriage? Talk it out. As Annmarie Cano, professor of psychology at Wayne State University, toldSELF recently: “Couples must develop a habit of knowing how they’re feeling, learning how to express it to the partner, and really listening in a non-judgmental way when the partner discloses emotions that might heighten the other partner's distress.”

Cano went on to explain in a recent TEDx talk that it’s not just the physical suffering that takes a toll on a person living with a chronic condition, but also the emotional burden. “How loved ones respond to them makes a big difference in their quality of life,” she said. “Specifically, our ability to pay attention and be with someone who is suffering has healing power.”